Last year, Apple banned the music sharing service GrooveShark from its App Store. This week, according to Ars Technica, Google banned it from the Android Market. Most Android users will still be able to get it if they want and iPhone/iTouch users can jailbreak their devices if they really want the app, but for all those people I have one word: Napster.

That's the message for users since, as Gigaom first described in 2009,

All of the songs streaming on the site were uploaded by users, and Grooveshark doesn’t police its waters for infringing content itself. Rather, Grooveshark relies on the takedown provisions of the Digital Millennium Copyright Act, meaning that it will stream a song until someone asks for its removal.

While Ars suggested that Google may be clamping down to avoid any more problems with federal regulators and copyright holders, I'm inclined to believe that both Google and Apple have a competitive interest, as well.

Apple, obviously, has iTunes and has invested a great deal of effort in deals with music companies. Google, on the other hand, has had rumors of a branded music service flying around it for some time now. It also isn't clear how this will affect Android's relationship with Amazon, the default music store for most Android phones and now a streaming music service (at least for legally purchased content).

Frankly, I'd be more inclined to see pressure from Amazon as a reason to dump the GrooveShark app. Amazon, after all, with it's awesome new App Store (arguably much better than Google's own Android Market) and Cloud Player has made itself the single most important player in the Android software ecosystem, aside from Google itself.

So whether GrooveShark is the next Napster or just another Pandora, and whether Google wants to avoid any more legal nonsense or it just wants to push competitors out of the picture, the company clearly has plenty of reasons to say goodbye to GrooveShark. In fact, like it or not, so do consumers.